If you’ve played Assassin’s Creed, you’ll be dimly aware of some stupid framing story that causes you to push the x-button furiously as you slaver for rooftop violence. The meat of the game concerns the titular assassin’s adventures in various period settings. You pilfer from courtesans in Renaissance Italy. You wave cutlasses at pirates in colonial times. Those sorts of awesome things. The present-day science-fiction yarn, which places the hero in a computer simulacrum, seems to exist solely to explain the old videogame convention of allowing players multiple lives. If you say so.

Among the many oddities of this strange, boring movie version is its unnecessary focus on that corner of the source material. It’s as if they made a film of Space Invaders and included lengthy sections involving the collection of change and queues behind the best player in town.

Justin Kurzel’s film begins with young Callum Lynch discovering his mother slain and his sinister father (more on Brian Gleeson in a mo) lurking guiltily in the shadows. Years later, now played by Michael Fassbender, Callum is a career criminal with a standard movie bad attitude.

Following his apparent execution, he is resuscitated and brought to a large white complex where a sleek scientist (Marion Cotillard) and her fruity father (Jeremy Irons) fail to explain a scheme that would confuse Dr McBoffin of Plot College, Oxford. Callum will relive the memories of a 15th-century ancestor who, during unhappy interactions with religious paramilitaries, encountered a magical item still desired by contemporary Knights Templar. Let us just type the words “Dan Brown on a bad day” and allow the reader to slump into a swoon.

When news came that the team behind the recent, gritty (if largely inaudible) version of Macbeth – Fassbender, Cotillard and Kurzel – were to move onto a videogame adaptation, hope sprang that we might finally get a decent film in that unlovely genre. Assassin’s Creed is better than most such projects, but it is still close to unendurable.

Cotillard does agreeably strange things with an accent that veers between American-French and English-French in adjacent syllables. Charlotte Rampling grits her teeth and thinks of the new patio she can finance with just three days work. Irons is probably having fun. Domestic viewers will enjoy seeing Brendan and Brian Gleeson playing Fassbender’s dad in different decades. All these actors are, sadly, trapped in an achingly dull amalgam of science fiction and conspiracy hokum that nobody (neither Assassin’s Creed fans, nor the uninvolved) asked to see.

The period scenes do look very much like those in the source. Adam Arkapaw’s cinematography suggests the grey-blue filter that game designers use when trying to emulate the appearance of movies. But this actually is a movie. So why bother? Fassbender climbs, drops and rolls in similar fashion to his digital equivalent. If all you require from a film is facsimile, then those scenes suit you nicely.

One is left wracking brains as to why these talented people wasted so much time. It’s not even the best videogame adaptation released in the past 12 months. Come back, Angry Birds. All is forgiven.